This invention relates in general to seals and, more particularly, to a two component seal which will accommodate large axial displacements.
The bearings on which work rolls of rolling mills turn operate in an extremely hostile environment, and the same holds true, perhaps to a somewhat lesser measure, for the bearings of the back-up rolls. These bearings must not only resist heavy radial loads applied by the rough shapes which pass between their rolls, but they must further withstand the severe impacts to which the rolls are subjected. Furthermore, the mills often operate with water cascading over their rolls and likewise over the chocks in which the bearings for the rolls are located.
The impacts encountered by a mill roll often translate into axial displacements between the mill roll and the chocks in which its bearings are housed. Some of the displacement produces deflections in the bearings themselves, while the rest is taken up in the end play with which the bearings are initially set and in axial clearances within the bearing mountings. In any event, the seals which keep contaminants out of the bearings must accommodate these displacements without admitting contaminants.
Traditionally, the seals for the bearings of mill rolls have been fitted to the chocks which house the bearings, and these chocks have adequate space to accommodate multiple seals which bear against the roll neck or wear rings around the roll neck. Lately, bearing manufacturers have fitted seals to the bearings themselves to provide an extra measure of protection for the bearings. The ends of the bearings offer little space for seals, and as a consequence the seals of necessity must be quite compact. Most have only one lip. Some require a separate seal carrier for the seal, and that is another costly part that can be damaged in storage or transit, and if so damaged, will admit contaminants to the interior of the bearing it is designed to protect.
The present invention resides in a two component seal that fits into the end of a bearing and has a plurality of seal contacts between the two components so as to effectively isolate a region beyond the seal. The one component may float axially relative to the other component within limits established by bumpers.